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Penguins that died 44,000 years ago in Antarctica have provided extraordinary frozen DNA samples that challenge the accuracy of traditional genetic aging measurements, and suggest those approaches have been routinely underestimating the age of many specimens by 200 to 600 percent. In other words, a biological specimen determined by traditional DNA testing to be 100,000 years old may actually be 200,000 to 600,000 years old, researchers suggest in a new report in Trends in Genetics, a professional journal. The findings raise doubts about the accuracy of many evolutionary rates based on conventional types of genetic analysis. “Some earlier work based on small amounts of DNA indicated this ... 
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Female plants were more likely to be colonized by the mycorrhizal fungi than male plants The war between the sexes has been fought on many fronts throughout time—from humans to birds to insects, the animal kingdom is replete with species involved in their own skirmishes. A recent study by Dr. Sarah Eppley and colleagues at Portland State University published in the November issue of the American Journal of Botany (www.amjbot.org/cgi/content/full/96/11/1967) demonstrates that certain plants, with some help from fungal friends, may also be involved in this fray. Most flowering plants form symbiotic relationships with mycorrhizal fungi. The plants produce food that the fungi need to ...
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All multicellular organisms require apoptosis, the controlled death of cells. Without apoptosis, 2 tons of bone marrow and lymph nodes and a 16-km intestine would probably accumulate in a human by the age of 80.1 Investigations into apoptosis have revealed complex interconnections between various cell-death programs, and these networks could affect the treatment of a wide range of diseases.2,3,4,5,6,7,8,9,10 Classification of Cell Death The most widely used classification of mammalian cell death recognizes two types: *apoptosis and * necrosis.3,4,11 * Autophagy, which has been proposed as a third mode of cell death, is a process in which cells generate energy and metabolites by ...
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El pez cebra es un clásico en los laboratorios de investigación animal. Las mejoras en el conocimiento de su proceso de clonación pueden tener implicaciones importantes en la investigación básica de muchas enfermedades. 31 de Agosto de 2009 Investigadores de la Universidad de Michigan investigan el proceso de clonación del pez cebra Investigadores de la Universidad de Michigan, en Estados Unidos, han desarrollado un método más eficiente para clonar el pez cebra. El trabajo, que se publica en el último número de Nature Methods, tendrá importantes implicaciones en la investigación básica debido a que gran cantidad de grupos utilizan a este pez como objeto de investigación. “Después ...
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Parents compensate for a lazy partner by working harder to bring up their offspring, but not enough to completely make up for the lack of parenting, says research by bird biologists at the University of Bath. In nature, it is quite rare for both parents to be involved in raising young, but it is very common in birds, some fish and primates including humans. Researchers therefore wanted to find out why, for some animals, parents stick together. The study, published in the Journal of Evolutionary Biology, analysed more than 50 previous studies of birds to understand why and how they share their parental duties. The research was led by Dr Freya Harrison and Professor Tamás Székely at the ...
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Deadly Diseases May Move Up Hawaiian Mountains to Birds’ Refuges As climate change causes temperatures to increase in Hawaii’s mountains, deadly non-native bird diseases will likely also creep up the mountains, invading most of the last disease-free refuges for honeycreepers – a group of endangered and remarkable birds. A just-published U.S. Geological Survey (USGS) review discusses the likelihood of a forthcoming “disease invasion” by examining the present altitudinal range of avian malaria and pox, honeycreeper distribution, and the future projected range of diseases and honeycreeper habitat with climate change. At one time, the Hawaiian Islands had no mosquitoes – and no mosquito-borne ...
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A ghostly property of matter, called quantum tunneling, may aid the quest for accurate, low-cost genomic sequencing, according to a new paper in Nature Nanotechnology Letters by Stuart Lindsay and his collaborators at the Biodesign Institute of Arizona State University. Tunneling implies that a particle, say an electron, can cross a barrier, when, according to classical physics, it does not have enough energy to do so. Unraveling the DNA sequences of the human genome a decade ago was a remarkable achievement. Today, the task of sequencing some 3 billion chemical base pairs of the genome—enough information to fill a 20-volume encyclopedia—remains a daunting challenge, thus far accomplished ...
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PASADENA, Calif.-- For the tiny soil-dwelling nematode worm Caenorhabditis elegans, life is usually a situation of feast or famine. Researchers at the California Institute of Technology (Caltech) have found that this worm has evolved a surprisingly optimistic genetic strategy to cope with these disparate conditions--one that could eventually point the way to new treatments for a host of human diseases caused by parasitic worms. As reported in a paper published in the February 26 issue of Science Express, Paul W. Sternberg, the Thomas Hunt Morgan Professor of Biology at Caltech and an investigator with the Howard Hughes Medical Institute, along with postdoctoral scholar L. Ryan Baugh, ...
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Miércoles 4 de marzo de 2009 FOTO Charles Darwin, según una foto tomada por J. Cameron en 1869 Foto: Archivo Elizabetta Piqué Corresponsal en Italia de La Nación ROMA.- Según el Vaticano, la teoría de la evolución de Charles Darwin no excluye que Dios pueda haber creado el universo. Lo afirmó ayer el cardenal William Levada, prefecto de la Congregación para la Doctrina de la Fe, al inaugurar en la Pontificia Universidad Gregoriana una inédita conferencia para marcar el 150° aniversario de la publicación de El origen de las especies, obra de Darwin (1809-1882). El convenio, que durará hasta el sábado y que juntó a teólogos, científicos, filósofos y académicos de todo el ...
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Charles Robert Darwin was born on February 12, 1809 (the same day as President Abraham Lincoln). In 1859 Darwin published On the Origin of Species by Means of Natural Selection (1), his most important book and the one by which he has become best known to posterity. Thus, 2009 is a double anniversary: the 200th of Darwin's birth and the sesquicentenary of Origin. Darwin is deservedly credited as the originator of the modern theory of evolution. In Origin he gathered the best available evidence for evolution: 2 chapters dedicated to the geological record, 2 chapters to biogeography, and 1 chapter to comparative anatomy and embryology. The other 9 chapters (I–VIII and XIII) are mostly ...
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It is often said that Darwin's theory of natural selection is unproven – True? I don't think that is a very useful question because Darwin's strength comes not so much from what he proved, but from the near-inescapable conclusions that he led us to. He used every means of informing himself about questions that interested him. He is known for his massive and continuous correspondence, always asking pertinent questions of those studying what we should now call model systems or model organisms. Of course, he was also a great natural historian himself, so his own observations pervade his writings. He was then able to integrate observations from one species into a prototype for what we now ...
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Nascimento do inimigo nº 1 dos criacionistas completa 200 anos Publicidade FELIPE MAIAda Folha Online Há exatos 200 anos, no dia 12 de fevereiro de 1809, nascia em Shrewsbury, no Condado de Shropshire (Inglaterra), o homem que iria revolucionar o estudo da ciência: Charles Robert Darwin. O trabalho dele, com a teoria da evolução das espécies por meio da seleção natural, não só lançou as bases da biologia moderna, mas também influenciou outras áreas do conhecimento, como a antropologia, psicologia, política e economia. A teoria da evolução proposta por Darwin no livro "A Origem das Espécies" chega aos 150 anos praticamente imbatível na comunidade científica --recebidas com receio ...
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Un investigador británico tiene una nueva explicación sobre cómo los seres humanos podemos mantener un equilibrio entre hombres y mujeres en la población: pese a la gran cantidad de varones jóvenes que mueren en guerras y al aborto selectivo de fetos femeninos en ciertas partes del mundo. Corry Gellatly, investigador de la Newcastle University propone que existe un gen que determina si un hombre tendrá más hijos varones, mujeres o igual cantidad de unos y otras. Cuando faltan mujeres en una población, ellas tienen mayor probabilidad de encontrar una pareja y son, por lo tanto, más propensas a pasarle a sus hijos el gen que aumenta la probabilidad de tener hijas mujeres. Y cuando ...
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Grâce au transfert vers l'insecte d'une bactérie nommée Wolbachia,des biologistes ont pu diminuer de moitié la durée de vied'un moustique dans les conditions de laboratoire. Crédit photo : James Jordan Sachant que seuls les insectes les plus âgés jouent un rôle dans la transmission des virus, des chercheurs ont réduit leur durée de vie de moitié en leur transférant une bactérie. Les chercheurs savent déjà que ce sont les moustiques femelles qui piquent les humains, se contaminant éventuellement à leur contact avec le virus de la dengue ou le parasite du paludisme. Ils savent également qu'après la piqûre, le virus de la dengue, par exemple, se propage dans le corps du moustique jusqu'aux ...
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Un extremadamente raras ranas ha sido hallada por primera vez en 20 años. La pequeña rana de árbol, Isthmohyla rivularis, fue visto en Costa Rica de Monteverde Cloud Forest Preserve. Esta especie se cree que se han extinguido hace dos décadas, pero el año pasado la Universidad de Manchester investigador capturado una visión de un rana macho. Sin embargo, el descubrimiento de las hemnbras y más machos sugiere esta especie es la cría y ha sido capaz de sobrevivir cuando las ranas, muchos otros no lo han hecho. Andrew Gray, un herpetólogo de Manchester Museo de la Universidad de Manchester, dijo: "Este ha sido el punto culminante de la totalidad de mi carrera. La única vez que nunca a ...
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Summary Progressive telomere shortening eventually results in chromosome fusions and genome instability as the cell's ability to distinguish chromosome ends from DNA double-strand breaks is compromised. In fission yeast, such events frequently produce stable survivors with all circular chromosomes. To shed light on the repair pathways that mediate chromosome end fusions and generate circular chromosomes, we have examined a diverse array of DNA repair factors. We show that telomere attrition-induced chromosome fusions are dependent on the fission yeast homologs of Rad52, the ERCC1/XPF endonuclease, the single-stranded DNA-binding protein RPA, and the Srs2 and Werner/Bloom helicases, but ...
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Summary Progressive telomere shortening eventually results in chromosome fusions and genome instability as the cell's ability to distinguish chromosome ends from DNA double-strand breaks is compromised. In fission yeast, such events frequently produce stable survivors with all circular chromosomes. To shed light on the repair pathways that mediate chromosome end fusions and generate circular chromosomes, we have examined a diverse array of DNA repair factors. We show that telomere attrition-induced chromosome fusions are dependent on the fission yeast homologs of Rad52, the ERCC1/XPF endonuclease, the single-stranded DNA-binding protein RPA, and the Srs2 and Werner/Bloom helicases, but ...
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ABSTRACTS: It was earlier proposed that an important anti-cancer mechanism of plant polyphenols may involve mobilization of endogenous copper ions, possibly chromatin-bound copper and the consequent pro-oxidant action. This paper shows that plant polyphenols are able to mobilize nuclear copper in human lymphocytes, leading to degradation of cellular DNA. A cellular system of lymphocytes isolated from human peripheral blood and comet assay was used for this purpose. Incubation of lymphocytes with neocuproine (a cell membrane permeable copper chelator) inhibited DNA degradation in intact lymphocytes. Bathocuproine, which is unable to permeate through the cell membrane, did not cause such ...
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Abstract Because emotions enhance memory processes and music evokes strong emotions, music could be involved in forming memories, either about pieces of music or about episodes and information associated with particular music. A recent study in BMC Neuroscience has given new insights into the role of emotion in musical memory.Minireview Music has a prominent role in the everyday life of many people. Whether it is for recreation, distraction or mood enhancement, a lot of people listen to music from early in the morning until late at night, especially since the invention of radio and recordings. Because of its near ubiquity, music has been identified as important in the construction of ...
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Researchers from several universities of the USA and China have sequenced for the first time papaya genome; they have also identified the DNA of a transgenic organism for the first time. Prestigious scientific journal Nature has echoed this research work in the cover of its last number. UGR News A scientific group of the Universities of Illinois (USA), Georgia (USA), Hawaii (USA) and Nakai (China), among others, have deciphered for the first time fruit genomic sequence, in this case papaya (Carica papaya), according to the cover of the last issue of the prestigious journal Nature. One of the researchers is a scientist assigned to the group of Molecular Genetics of the Department of ...
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